Spinal deformity can lead to loss of stability and upper body function, including a decrease in respiratory capacity. Effective non-invasive procedures for measuring and recording spinal/pelvic alignment of a seated person are unavailable. The focus of this proposal is to describe a new method of measuring spinal/pelvic alignment using a radio frequency carrier phase measurement technique. To utilize this method a person remains seated in his or her own personal wheeled mobility device. Small, flexible transmitting antennas are taped to prominent landmarks on the spine. Receiving antennas are strategically placed behind the person's wheelchair. Once processed, the received signal provides data to allow accurate three dimensional measurement of a person's spinal/pelvic alignment. PROPOSED COMMERCIAL APPLICATION: The development described in this proposal has potential commercial applications in the rehabilitation marketplace. The device will make it possible to track, the spinal/pelvic alignment of an individual over time, therefore indicating if there may be a problem with the person's seating system, or if a change in therapy techniques is warranted. Hospitals, physical therapy clinics, and assistive technology clinics would all be interested in having the capability to monitor spinal/pelvic alignment. A manufacturing partner will he sought during phase II to bring the device to the marketplace.